Plate 7. Vine thicket (type 3),Goodedulla National Park, west of Rockhampton (site 73). Note browning and loss of foliage due to extreme drought conditions (August 1994). Species include Backhousia kingii, Crown insularis, Owenia venosa, Geijera paniculata and Acalypha eretnorum (foreground). - - Plate 8. Interior of (type 3) vine thicket, "Cerberus", west of Marlborough (site 67). Species include Backhousia kingii, E.vcoecaria dallackyana, Guettardella putaininosa and Planclunzella cotinifolia var. pubescens. 142 CHAPTER FOUR A REGIONAL CONTEXT FOR VINE THICKET COMMUNITIES - FLORISTIC PATTERNS IN THE BRIGALOW BELT BIOGEOGRAPHIC REGION AND RELATIONSHIPS WITH ENVIRONMENTAL ATTRIBUTES, PARTICULARLY CLIMATE. Although the core area of distribution and major remnants of semi-evergreen vine thicket are located in central and southern Queensland, outliers of these communities occur extensively in the northern and southern Brigalow Belt Biogeographic Region. Time and other constraints resulted in the southern (i.e. north-western New South Wales) vine thickets being excluded from the detailed field survey (Chapter 3) and in the northern vine thickets being relatively under-sampled. The latter areas have since been included in a comprehensive floristic survey of northern inland vine thickets by Fensham (1995). Floristic data are available for several southern vine thicket locations (Floyd 1991, J.B.Williams, unpubl. lists), three of which were included in Webb, Tracey and Williams (1984) floristic analysis of Australian rainforests. It was considered desirable to test the robustness of the vine thicket classification/typology derived above (Chapter 3) using an enlarged floristic data set compiled across the entire Brigalow Belt Biogeographic Region. Inclusion of site data from Fenshams (1995) survey has two purposes; (i) to improve the intensity of sampling from the northern Brigalow Belt Biogeographic Region (see above) and (ii) to provide an opportunity to compare the vine thicket classifications from this study and that of Fensham, using a common data set. Webb et al. (1984) described several floristic subunits (elements) within the northern Australian vine thickets (B3 ecofloristic province). They also referred to, but did not describe, elements within the C2 province, which closely approximates in geographical extent the central and southern Brigalow Belt Biogeographic Region. A regional floristic analysis, using a larger data set than that previously available, may thus provide definitions of subunits, i.e. a finer spatial resolution, within the framework established by Webb et al. (1984). A preliminary study of climatic relationships in Australian rainforests was undertaken by Nix (1993). Structural data for 644 sites, essentially a slightly expanded version of the data set used by Webb et al. (1984), were matched against an analysis of climatic indices generated for each site 143 using BIOCLIM (see section 3.3.3). The climatic framework developed by Nix corresponded relatively closely with the main groups of Webbs (1968) structural types. Semi-evergreen vine thicket sites formed one of three rainforest types within the subtropical (mesotherm) group, occurring on soils of high nutrient status under relatively low rainfall conditions (Nix 1993). Nix, Stein, McMahon, Tassell and Hodges (1992) later undertook an agglomerative classification of a subset of 290 sites (the mesotherm group), which was broadly equivalent to the combined C 1 and C2 floristic provinces of Webb et al. (1984). Nix et al. described 10 floristic groups, with vine thicket (SENT) sites concentrated in their groups 1 and 2, which contained 71 and 17 sites respectively (see Table 4.11 below). The present study sets out to identify floristic patterns in vine thicket communities throughout the Brigalow Belt Biogeographic Region, and to place within this context the community-types described in the previous chapter. Floristic sub-groups within the northern Brigalow Belt are compared with the results of a complementary study by Fensham (1995). The study also seeks to determine relationships at the regional scale between floristic patterns and climatic factors. 4.1 The data set Additional site lists were gathered from several sources. Many vine thicket remnants visited during the detailed survey (Chapter 3) were found to be too small and/or fragmented for meaningful quantitative data to be gathered. Several locations were checklisted in the northern Central Highlands, including the Zig Zag Range north of Bogantungan, "Taunton" and Charlevue Creek near Dingo and a group of sites in the Nebo-Moranbah district (see Table 4.1). Although vine thickets were not extensively developed in the northern Brigalow Belt Biogeographic Region in comparison with areas south of the Tropic of Capricorn, it was felt nonetheless that the northern stands were undersampled for a regional study. A representative subset (30 sites) from the floristic survey undertaken by Fensham (RJF) (Fensham 1995) was added to the database. These sites were located mainly in the Northern Bowen Basin and Marlborough Plains biogeographic provinces (see Figure 3.1), but also included the Peak Range and Mt Narrien, north of Alpha, the most inland occurrence of vine thicket in Queensland. 144 In northern New South Wales, lists for several vine thicket sites have been published by Floyd (1990) (A0F) and Benson (1995) (JB) (for Cadellia pentastylis communities). Other unpublished lists were made available by J.B. Williams (JBW) - these were also included in the analysis by Webb et al. (1984). Forster, Bostock, Bird and Bean (1991) (WWF) published lists for 232 vine forest and vine thicket locations in south-eastern Queensland. Most of these lists were compiled from traverses through patches and along their margins with up to 10 hectares being intensively listed. This contrasts with the narrowly defined sites in the present survey and that of Fensham and is reflected in the relatively larger number of species recorded for each location by Forster et al. (e.g Nangur State Forest (S059) - 124 species vs 73 in the present study). Lists were selected for several small vine thicket remnants, mostly in the Southern Subcoastal Lowlands province (see Table 3.1), e.g. Boonah and Marburg districts. Table 4.1 lists the 160 sites included in the bioregional database. Detailed map references (1:100 000 topographic series), altitude in metres and parent materials for each site are given in Appendices 3 and 4. The database was restricted to trees, shrubs and vines/climbers, as it was felt that records for other lifeforms were generally incomplete. Epiphytes, herbs (including ferns) and subshrubs were not recorded in a consistent fashion across the sites and were therefore excluded from the analysis. It has already been noted that seasonal conditions and grazing pressure have a major influence on the ground stratum in these communities. Floristic data from 136 subplots in the detailed vine thicket survey (see Chapter 3) were combined into 75 site-lists (S001-S075). These lists also incorporated any additional tree, shrub or vine species noted in the immediate vicinity of the subplots. Records of Cassine australis from moister vine thicket sites published by Forster et al. (1991) did not stipulate the particular subspecies. Since both subsp. australis and subsp. angustifolius are known from these localities (Queensland Herbarium records), it was necessary to combine subspecies records for the entire data set. Table 4.1 List of 160 vine thicket sites and their site-groups from 2 classifications based on species presence/absence data. SITE CI 1* CI 2 LOCALITY SITE CI 1 CI 2 LOCALITY S001 1 2 Portion 64 Woroon W of Windera S037 2 6 Bullaroo Creek N of Injune (Carnarvon NP) S002 2 6 Mt Narayen Narayen Research Station (Narayen A) S038 3 6 East Palmgrove (Palmgrove A) S003 2 6 Dingo Trap Hill Narayen RS (Narayen B) 5039 3 6 Central Palmgrove (Palmgrove B) S004 2 6 Koko Scrub State Forest 40 SO40 3 6 Palmgrove Creek (Palmgrove C) S005 2 2 Wonga Hills SO41 3 7 "Welcome" Section Carnarvon National Park S006 2 2 Cracow Mine 5042 3 7 "Telemon" Springsure S007 3 7 Brigalow Research Station SO43 8 7 Bonewood Site "Bonnie Doon" (Bonnie Doon B) S008 3 7 Oombabeer Bauhinia Downs SO44 3 7 Belah Site Dipperu National Park (Dipperu B) S009 2 6 Bauhinia Ck W of Gogango Range Capricorn Highway SO45 6 6 E of Denison Creek Nebo-Sarina Road S010 3 7 South Blackwater ooline site 5046 5 4 Mount Britten "Homevale" S011 3 7 Wallalee Springsure SO47 6 8 Blenheim Creek S012 3 6 Lake Nuga Nuga bonewood site (Nuga Nuga A) SO48 7 9 Mingela Bluff "Maidavale" E of Mingela S013 3 7 Lake Nuga Nuga ooline site (Nuga Nuga B) SO49 2 6 Northern Scrub Isla Gorge National Park (Isla Gorge A) S014 3 6 Dawson Highway Expedition Range S050 3 6 Ridge Site "Bimbadeen" Taroom (Bimbadeen A) S015 2 6 Cannondale Mt Expedition Range National Park S051 3 6 Scrub Belt Site "Bimbadeen" (Bimbadeen B) S016 2 6 Transect Scrub Amphitheatre Expedition Range NP S052 3 6 Upper Zamia Creek Palmgrove National Park S017 3 6 Glenleigh E of Glenhaughton S053 2 6 Gurulmundi Ooline Reserve S018 3 6 Gerrards Scrub Glenhaughton Road S054 3 7 Broad Gully Creek Scrub Ka Ka Mundi (Carnarvon NP) S019 2 2 South Mundubbera S055 3 7 Bottletree Flat Ka Ka Mundi S020 2 2 "Oakpark" W of Eidsvold S056 3 7 Upper Vandyke Creek "Kareela" S021 1 1 Yarrol Scrub Monto S057 2 6 Southern Expedition Range near "Yebna" S022 4 3 Koolkoorum Scrub Ubobo S058 2 6 Devils Nest Scrub Isla Gorge National Park (Isla Gorge B)